DRIVERS-3454 : Summary of necessary driver changes When tracing is enabled, attach the command span's W3C traceparent to each command as a new OP_MSG Payload Type 3 (telemetry) section: { "otel" : { "traceparent" : "<55- char value>" } } so server spans join the driver's trace as children of the exact command/retry attempt. Attach only when: tracing enabled + maxWireVersion >= 29 (MongoDB 9.0+), otherwise omit the section entirely. Note : The server-span prose tests (5–7) require the latest drivers-evergreen-tools orchestration ( DRIVERS-3605 , OTEL=1) to start mongod with OTel enabled and export OTEL_TRACE_DIR , without it the tests skip. Commits for syncing spec/prose tests https://github.com/mongodb/specifications/commit/a9adc41b6eed59fd1197e852a2d8dccc4eaf16fb Java reference implementation https://github.com/mongodb/mongo-java-driver/pull/2022 Context for other referenced/linked tickets DRIVERS-3605 OTEL=1 orchestration in drivers-evergreen-tools: configures the server's OTel file exporter and exports OTEL_TRACE_DIR; prerequisite for prose Tests 5–7 (needs a 9.0+ OTel-enabled mongod build). SERVER-107128 / SPM-3868 server side: {OP_MSG}} trace-context ingestion and validation